Skills

RFID Reader ID-3LA (125 kHz)

Description: RFID (radio-frequency identification) is the wireless non-contact use of radio-frequency electromagnetic fields, for the purposes of identifying and tracking tags attached to objects. This is the ID-3LA, a very simple to use RFID reader module from ID Innovations. The only holdups are the 2mm pin spacing and you will need an external antenna. Power the module, hold up a 125kHz card, and get a serial string output containing the unique ID of the card.

Note: The new ID-3LA is essentially the same as the ID-2, but has a lower voltage input.

If anybody is looking to connect this to a Raspberry Pi it’s pretty easy. Use one of the 5V pins from the header to power it, along with ground and then just connect the TX pin of the rfid module to the RX pin on the Pi header. I’ve created a Python module that makes interfacing with the reader quite simple.

I am working on a project where two objects need to identify each other when close-by. I plan to use this RFID reader along with RFID Tag for each object. So, when two objects (say A & B) come closer, A’s reader reads both tags (A & B) while B’s reader also reads both tags (B & A) and thus by eliminating self tags, objects can identify each other. Would this RFID reader be suitable for such application ? Any problems of interference ?

What is the Power consumption of ID-3LA? This is not specified in the datasheet.

I have done a 1.33 mH coil (44 Ohm serial resistance) and connected it to the module using a 3.0 V supply. It reads tags nicely. I measure the current consumption to about 10 mA. Can I trust this to be a relevant number using my coil design? I guess that a coil with lower serial resistance will increase current consumption, but I’m happy with my current coil (the reading distance is more than enough). Or is there a risk that more current is consumed than what I measure?

I hand-built a coil and documented for posterity’s sake, and my dodgy memory, in excruciating detail here.

I’m using a 5V supply and got about 6.5".

How did you measure current consumption? I’m doing to some calculations that when they make sense I’ll post. I put a 1.6 ohm (supposedly 1.5) resistor in series with the coil and measured a Vpp of 55.2mV. That would be about Ipp of 30mA.

That does kind of jive with your numbers. Irms across the resistor was 11.5mA. Rdc of my coil was 3.9 ohms.

I’m going to try to remember how to go from Vpp across the inductor to current. I believe that reactance figures into things.

Customer Reviews

5 out of 5

Best RFiD Product to match a craftman antenna

I found this Reader very versatile when time’s is come to match an antenna on it. With this Reader I have been able to get a 15 inches read distance with an Eye Key Fob Tag.
The construction of the antenna:
A 10x10cm Antenna with a 0.034AWG copper wire (Round Form)
Inductance of 1.33Mh
Around 80 turns of wire, (winding has to be very close)
An external offset capacitor have been use for mine(47PF)
A 70 volts Peak to peak was generate from the Reader(MAX 80v) with a 50MA drawn from the antenna
a series resistance of 4,2OHMs have been use with the antenna to drop the antenna current at a safe level(50MA)
NO short PCB plane (short turn) have been use to calibrate the antenna only a offset capacitor have been use.
We used the TTL Data encoding to communicate with a Basic Stamp controller(ASCII data structure).

Power use: 5v
current consumption:
(Idle) 50ma
(On read) 180ma

Prototypes(50 unites) made with it was use to monitor Drinking habit’s of piglet at a study research farm.

The two problems found was the cost and the non-standard pins configuration of the ID-3LA socket, the 2MM space pin is not standard to DIP form , we had to manage a socket form for it in PCB software.

Communication performance:
The use of a buffer line wasn’t needed.
we have been able with a micro-controller to communicate with the IC reader with a 25' foots flat 5 contacts cable(no shield protection) without communication errors.

En brief
Very easy to use and manipulate.
we didn’t work with the Wiegand26 and Magnetic ABA Track2 data formats protocol , some shield protection might be take in consideration if you intend to use the Magnetic ABA protocol since timing is critical with that form.

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